P/J Bass wiring schematic help (is this possible?)

Discussion in 'Pickups & Electronics [BG]' started by TC2112, Jul 31, 2009.

  1. I have 3 fender P bass specials from the late 80's with passive P and J configurations. I know that they underwind the P so it does not overpower the J in this type of design, and the additional resistance in the J pickup electronics cause the P pickup (plus the underwinding) to not have the punch of a typical P bass.

    with all that understood, I would like to know if I could put in a alnico standard P bass pickup and a 2 way mini-toggle, with one side being the p bass pickup only, completely bypassing the J pickup and pots, and the other side being the original type wiring where I could blend in a little bridge pickup growl along with the P bass type pickup? If this is possible, could someone show me a wiring scheme? If not, then I am probably just going to replace the weak P bass pickup and wire it straight and take the jazz completely out so I can get my P bass tone.

    Thanks for any help that's out there
  2. WingKL


    May 12, 2007
    Another option you might want to consider is a volume, pickup selector, tone setup. The pickup selector setup replaces the blend control with a 3 way rotary switch which selected for P only, blend and J only pickup. I like my modified setup as it gives me a nicer tone, almost like an active setup without using a preamp.
  3. thank you, but I guess I don't completely understand this drawing? It sounds exactly like what I am looking for, but this only shows what I am assuming to be the push / pull pot, but it doesn't show where any of the other wires lead to. do you have a complete wiring diagram, or am I just too thick to realize this is all I need.

    Thank you again for your assistance
  4. I don't have a blend pot, they are wired like a standard Jazz with 2 volumes and a tone. If I use the three way rotary then I lose the ability to control and vary the amount of Jazz pickup I bring in, and I don't really want to give up that option, plus I am not sure if that eliminates the additional loss of resistance through the additional pots. Thank you for the response.
  5. My personal preference is the two volumes plus a pickup selector switch configuration.

    You get the traditional P vibe with the P soloed, and the traditional J vibe with both volumes on, and the P rolled all the way down.
  6. Sure, i can draw you a diagram if you give me a day or so to do so.

    As far as the 3 way switch losing the ability to blend pickups, what you want is a VVT setup with the pickup selector, so you can still vary the volumes, but solo the P for the traditional one volume-one tone setup.
  7. That would be fantastic - Thank you

    so would that be a three way toggle with <P solo / both on / J solo> or just simply a 2 way with <P solo / all on>
    I guess either way is fine, but I was hoping to keep it as simple and unobtrusive as possible. I love the idea of just using a push / pull pot to solo the P bass with no other visible mods to the bass
  8. You could do any of the three ways you mentioned, but since you're inclined toward the push/pull P solo switch, that's probably what you would be most happy with.

    I can draw your diagram tomorrow.
    Do you want the switch on the P pickup's volume pot, or the J pickup's volume pot?
  9. I would think that the J pot would be easier, with it being wired that out is the solo P. That way I wouldn't hit it accidentally when using the p bass controls. push it in and everything is on, so the jazz controls are in play and no mistakes. does that make sense?

    since you are so willing to help (and I do appreciate it very much, thank you), I will pick your brain one more time. What size pots would you recommend for a set up like this and are you a believer in the PIO caps or are the ceramic jobbies just as servicable?
  10. Alright, here is your diagram:

  11. What size? Well, whatever size fits the holes you have on the bass.
    Make sure that your knobs fit the shafts too, because there are actually 2 sizes.

    Or do you mean what value?

    The difference between capacitors is that very cheap caps can have terrible tolerances, which is why some people say that the expensive caps sound so much better than the crappy ceramics that came on their instrument.

    Don't buy into the expensive capacitor hype. As long as you have a decent capacitor, it will sound just as good as an expensive one.

    I recommend Orange Drop capacitors. You can get them for about $1.50
  12. yes - I did mean what value

    500 , 250? anything else?
  13. Ok one more time then I'm done -

    so using this long story logic, then I should use V1 = 500k, V2 (push/pull) = 1meg, T=500k

    that way - with the P bass solo, I am using 2 500k pots to equal 250k. with both pickups on and all three pots in play, I am still very close to the 250k.
  14. When the P is soloed, the Jazz's pot is removed from the pot, giving you the traditional one volume-one tone setup that a P bass usually has.

    With the Jazz in the circuit, you get the two volume-one tone setup that is traditional to most Jazz basses.

    There is no need to play with different values to get the traditional output from the bass.
    All 250K's would be traditional, and 500K's will make it hotter/brighter.
  15. great -
    thanks. hope this helped anyone else with a P/J config.
  16. robthegaff


    Nov 29, 2009
    Its certainly helping me :)
  17. JTE

    JTE Gold Supporting Member

    Mar 12, 2008
    Central Illinois, USA
    Hmmm... If it's a stock MIJ Fender Jazz Bass Special, it already has this. The stock set up was a V/V/T with a 3-way toggle. I'm not sure what you accomplish with this change (other than getting rid of the TBX). Also, my experience with those basses is that the P coils were the same as the ones on the regular MIJ Precisions of the time- not underwound at all.

  18. Lukejt


    May 24, 2008

    I just gutted my active P Special Deluxe to make it passive and have been trying to decide what to order.